The mammary gland is a compound tubuloalveolar gland. The secretory
parenchyma is divided into lobes and then lobules by connective tissue
septa. The secretory acini release their contents into intralobular
ducts (too small to be seen here) which drain into the lobular duct
(center of picture). This then drains into a lobar lactiferous duct
(not seen here). In the lactating mammary gland, the secretory acini
have lumens containing milk. Some of the acini have fused together.
PK4892B-05. Original mag. 16x. H&E. Lactating mammary gland. Female
Reproductive System.